SPARK Cost of Initializing Database Connection in map / mapPartitions context

Question

Examples borrowed from Internet, thanks to those with better insights.

The following can be found on various forums in relation to mapPartitions and map:

Answer 1

In my opinion, connection should be kept out and created just once before map and closed post task completion.

val connection = new DbConnection /creates a db connection per partition/

val newRd = myRdd.mapPartitions(
  partition => {    

    val newPartition = partition.map(
       record => {
         readMatchingFromDB(record, connection)
     })

    newPartition
  })

connection.close()